The tablet seems really nice. I also found a deal for it here: http://dealsnow.info/2015/08/14/teclast-x98-pro-best-windows-10-tablet-currently-available/ The price is cheaper than any other place and it offers a 5$ discount. Considering Windows 10 is pre-installed on the device this is truly a best-buy :)
The Teclast X98 3G was amazing. I was waiting for the Cherry Trail version and it's finally here ! :) Soon the Aliexpress price will cut to around 220$ and I'll get this one. Just remember that usually the Chinese tablets have some bugs at the beginning but they are always fixed pretty quick.
I got a Nationite MIDnite a few years ago. Those were made by Witstech and unfortunately they went out of business. Funny thing is that my tablet still works, but it's bricked and I can't find a compatible firmware anywhere. Not that I bothered too much asking, I got a new cheap KitKat 7-incher with Intel Atom Z2520 and works like a charm after almost a year since I got it.
The problem with Chinese tablets is that, usually, software support is (very) limited to none, but if you encounter hardware problems, they usually repair/change them without making too much fuss about it.
While you could go search for tablets on AliExpress or DX, I would rather go with more specialized, smaller resellers. My recommendations would be Chinavasion and MP4Nation.